This invention relates to the control of intercom systems for motorcycles and other vehicles.
Intercoms allowing the driver and a passenger of a motorcycle to communicate with each other by means of speakers and microphones mounted in their helmets are well known. It is also well known to use the same speakers and microphones to allow the driver and the passenger to communicate with others by means of a CB radio, and/or to utilize the speakers to allow them to listen to entertainment audio which may be selected from audiotape players, CD players, MP 3 players and AM/FM radio. An example of the controls for such a multifunction audio system is described in U.S. Pat. No. 6,225,584. Voice actuated (VOX) circuits such as those described in U.S. Pat. No. 4,754,486 are often included in such multifunction audio systems to reduce or eliminate the entertainment signal to the speakers when one of the microphones or the CB receiver is actuated.
When using a multifunction system of the type described above, it will often be considered inconvenient to have the intercom on only when communication is desired. However, leaving the intercom in the “on” state can result in the undesired transmission of sounds originating from one of the users or from the environment. Such undesired transmissions can be annoying in themselves and may also degrade the entertainment audio by undesired activation of the VOX circuitry. Safety is a concern if the intercom volume control is used to eliminate undesired transmissions, since this requires the driver to remove a hand from the handlebars to access the volume control, which is usually located in the center tank area of the motorcycle. This can result in the driver having one hand removed from the handlebars for a significant amount of time.